A Novel Idea to Transform the Sahara
Large-scale wind farms in the Sahara could increase rainfall and vegetation in the area.

As anthropogenic global warming continues to affect and influence the climate across the world, it’s important to find ways to mitigate that effect. Sure, it would take a huge amount of effort to reduce the level of carbon dioxide in our environment, especially when we are still dependent on non-renewable resources. However, the number of global renewable energy plants are increasing at a rapid rate. Not only does such solar and wind farms reduce our dependency on coal, they also have effects on the heat and humidity of localized regions. A recent study by researchers from the University of Illinois and the University of Maryland have found out that an installation of wind and solar farms on the Sahara desert could change the climate in the region for good, in addition to generating massive amounts of power.

The study, published in the journal Science, is one of the first in the world to develop a model that studies the effect of wind and solar power installations on the climate. The model also takes into account the response of vegetation to changes in temperature and precipitation. Yan Li, the lead author of the study and a postdoctoral researcher at the University of Illinois, says, “Previous modeling studies have shown that large-scale wind and solar farms can produce significant climate change at continental scales, but the lack of vegetation feedbacks could make the modeled climate impacts very different from their actual behavior.”

After the model was developed, the researchers had to choose a region that was sensitive to the effects of such solar and wind farms. The Sahara desert, the largest in the world, was a good choice because of its low population and high sensitivity to land changes. Its close proximity to Europe and the Middle East provided another reason as well – as these areas have a large and growing energy demands.

In the study, the researchers simulated wind and solar farms across the Sahara and neighboring Sahel desert covering more than 9 million square kilometers. The results from the model indicate that wind farms caused warming of near-surface air temperature in the region, with greater changes in minimum temperatures than maximum temperatures. The authors wrote, “The greater nighttime warming takes place because wind turbines can enhance the vertical mixing and bring down warmer air from above. Precipitation also increased as much as 0.25 millimeters per day on average in regions with wind farm installations.”

The average rainfall over the region increased 0.5 inches per day, double of what was observed in control experiments without wind farms. The increase in rainfall led to an increase in vegetation cover, which provided a positive feedback loop on the precipitation. The increase in rainfall was a result of complex land-atmosphere interactions that occurred when large-scale solar and wind farms were simulated in the model.

In 2017, the global energy demand was estimated to be 18 terawatts. The simulated solar and wind farms combined to produce 81 terawatts of power, enough to sustain the requirements of the world. Thus, installation of solar and wind farms on the Sahara could not only increase rainfall and vegetation but could also reduce dependency on coal and provide the economy with clean energy.